Allison 6spd

[JDKing]

ok we have a 1994 Safari Sahara 5.9 cummins, with an allison 6sp. on the remote for the tranny there is a button marked mode. what does this do? all the remote has is a r/n/d button with arrows up/down and this mode button. is there a park in there somewhere?

[historyljc]

That's the selector between "power" and "economy" modes. All it does it to move the shift points so that in the "economy" mode the transmission doesn't downshift as soon. It's good for small hills (rises) and most overpasses. The default setting is normally "power" mode. I haven't used my "economy" mode enough to tell if it makes any real difference in fuel mileage.

There is no park. Put it in neutral and set the parking brake.

[JDKing]

thanks i will have to play with that on our next/first trip...

now whats the thing on the back of the tranny that looks like a torque converter?

[cannon man]

"E" brake?

[dbarton291]

Quote:

Originally Posted by JDKing thanks i will have to play with that on our next/first trip... now whats the thing on the back of the tranny that looks like a torque converter?

If it is in a finned housing, it's probably an output retarder. If it's a brake drum looking thing, it's the parking brake.

[JDKing]

gonna be the e-brake then... thanks! one more thing of what is it off my list!

[Dennis Wells]

No, No, No not a E brake, just a different shifting time, I would ignore it, but I am not the brightest on the block.

[dbarton291]

Which model transmission is this? MD3000 or 1/2000?

Does the vehicle have hydraulic or air brakes?

[JDKing]

Quote:

Originally Posted by dbarton291 Which model transmission is this? MD3000 or 1/2000? Does the vehicle have hydraulic or air brakes?

not sure what tranny it is, and it had hyd disc brakes.

[EngineerMike]

The Mode button moves the shift points as cited above. For an in-town delivery vehicle that does a lot of stop & go that could be useful. For a motorhome it won't make any difference, maybe a gallon of fuel a year. If Allison made a shift pad w/out the Mode button, they'd sell it to coach manufacturers, but they don't have one.

[dbarton291]

Quote:

Originally Posted by JDKing not sure what tranny it is, and it had hyd disc brakes.

Well then the brake drum looking thing on the back of the transmission is most likely the parking brake unless the vehicle has some way of holding the vehicle brakes.

[dbarton291]

Quote:

Originally Posted by EngineerMike The Mode button moves the shift points as cited above. For an in-town delivery vehicle that does a lot of stop & go that could be useful. For a motorhome it won't make any difference, maybe a gallon of fuel a year. If Allison made a shift pad w/out the Mode button, they'd sell it to coach manufacturers, but they don't have one.

Allison proposed a strip selector and motorhome manufacturers hated it. A strip selector is the range buttons only. Coach manufacturers typically want all the bells and whistles. They like the dual LED display, the mode button, remote digital display units, etc.

The market that goes for the simple selectors is the city bus market.

The mode button can be programmed to do lots of things. Dual shift schedules, which is common to motorhomes, is just one example. It can be used for pump mode in a fire truck, D1 hold, neutral lockup, lots of stuff.